α-d-Glucose-1,6-Biphosphate Induces Dendritic Cell Homing to Enhance the Antitumor Effect of Neoantigen Vaccines

Neoantigen vaccines have achieved good therapeutic effects in animal experiments and early clinical trials on certain malignant tumors. However, their overall objective effectiveness in clinical trials still needs to be improved. Low-efficiency dendritic cell (DC) migration (<5%) to lymph nodes is one of the factors that limits vaccine effectiveness. For neoantigen vaccines, improving the homing efficiency of DCs is expected to further improve the immunotherapeutic effect. In this study, we used α-d-glucose-1,6-biphosphate (α-d-Glu), a metabolite that successfully enhanced C57BL/6J mouse bone marrow-derived DC homing induced by neoantigen peptide, mRNA, and DC vaccines during the administration process and improved the antitumor effects in the mouse C57BL/6J model with a neoantigen vaccine. We clarified that α-d-Glu activated MAPK8IP1 by inhibiting the expression of microRNA-10a-5p, thereby activating the MAPK signaling pathway to promote DC homing. Excitingly, the efficiency of α-d-Glu in promoting DC migration is not weaker than that of PGE2, which is the gold standard used to promote DC migration in clinical trials of DC vaccines. Thus, this study lays the foundation for further enhancing the objective clinical response rate of neoantigen vaccines and overcoming the limitation of an insufficient clinical response rate for neoantigen vaccines caused by low DC homing efficiency.